Melancon is the one who got away this offseason, taking a much richer deal to sign with the San Francisco Giants. Distance, time, and poor performance could make the heart grow fonder, but there’s little reason to believe in a deal like this will happen.

First of all, Melancon is still owed most of the record $62 million he signed for in San Fran, a deal that the Giants deferred through 2028. The Nats are in win-now mode but will be unlikely to want more deferred deals like the one signed by Max Scherzer. This mortgages the future.

Also, Melancon is pitching well but not great, carrying a 2.53 ERA, his highest season mark since 2012. The Giants would be making a short-sighted move by reversing course and selling low, a move that could hurt them in future free agent negotiations.

Robertson, at times, seemed like an inevitability to join the Nats via trade during the offseason, but talks cooled after the White Sox wanted another top prospect in addition to the package that landed outfielder Adam Eaton.

The good news is that the Sox are unlikely to compete this season and Robertson is a likely trade candidate. If his asking price goes down and the Nats continue to struggle, look for some sort of deal to happen, but perhaps not to D.C.

Of the remaining bunch, there is intrigue aplenty.

Osuna is 22 years old and controllable through 2020. There’s little incentive for the Blue Jays to part with him for less than a top prospect or two.

Herrara comes with the added benefit of postseason success and a World Series ring that he won with the Royals in 2015. The Royals seem close to a rebuild, but Herrara, with two years of control left, will not come cheap.

Colome is coming off of a terrific, All-Star 2016 season, but is also controllable through 2020. The Rays are not averse to trading quality pieces, but it is always for young talent in return. This trade seems unlikely.

Ramos is a familiar foe and could be one of the more likely options for the Nats to target. He is also controllable through next season only and is making a manageable $6.5 million this season. While a trade within the National League East would be unusual, the permanently cash-strapped Marlins are most likely to consider such a proposal.